Endocrine Abstracts

Introduction: Graves’ orbitopathy and ocular myasthenia gravis are autoimmune disorders with overlapping clinical features that lead to difficulty in distinguishing both conditions. The simultaneous occurrence of both diseases is rare in frequency and occasionally followed by challenging management especially in pre-existing type 1 diabetes mellitus patient. We reported the case of ocular myasthenia gravis developed during the treatment in a patient with Graves‘ orbitopathy and type 1 diabetes mellitus.

Case report: A 23-year-old man presented with binocular double vision following bulging of his right eye and blurred vision since four months before admission. On examination, he was noted of having right eye proptosis and retro-orbital discomfort, with both eyes ophthalmoplegia related to partial oculomotor nerve palsies without pupillary involvement. Decreased visual acuity with dyschromatopsia were observed on both eyes. Paracentral scotomas were also revealed on Humphrey visual field examination. The diagnosis of dysthyroid optic neuropathy was made based on clinical signs and symptoms with laboratory findings concerning thyroid dysfunction. Corticosteroids as initial management was given under close observation along with insulin therapy considering the patient also suffered from type 1 diabetes mellitus. Clinical condition was worsened despite the treatment. Bilateral fatigable ptosis and general weakness were developed a month later. Diagnosis of ocular myasthenia gravis was confirmed based on clinical examinations and decremental response of repetitive nerve stimulation. Acetylcholinesterase inhibitor and plasmapheresis were added in the treatment. Ptosis and weakness were slightly improved but diplopia and visual function were moderately unchanged.

Conclusions: Detecting coexistence of Graves’ orbitopathy and ocular myasthenia gravis is important in establishing comprehensive management of both diseases. Worsening condition in a patient with type1 diabetes mellitus as the risk factor may require specific treatment to obtain favourable outcome.